paradigm shift

Steering helms are not to technical. It is a hydraulic pump with the drive connected to the steering wheel via a spring centered valve. If you have an idea of what a gerotor type pump is it will help. You have the pump section connected to a spool valve held in a centered position with a spring. The more force you put on the steering wheel over comes the spring centering presssure allowing the spool valve to open ports for the oil to flow to the cylinders under pump pressure creating hydraulic assist. Probably not the best explanation.

You could tee in some gauges in the cylinder lines and see if you get full pump pressure. You should see full pressure on one side and low return pressure on the other. Another gauge in the pressure line from the pump to the helm would be a good reference for the pressure side on cylinders.

Just remember that just because you have pressure does not mean you have flow. Two different parts of this equation.

Low return flow you mentioned would be normal if the cylinders are bottomed out. When they are moving you should see full flow.

http://hydraulics.eaton.com/products/steer_main.htm

Good luck!!

Wanted to say thet are not the easiest to trouble shoot with out the testing equipment and some expierance with them.

Falcon

I know this is basic, but is there a filter in the system? It should be somewhere in the high pressure pump line to the helm. If there is one and you haven't checked it, remove the internal filter cartridge, put it back together and retest.

If the flow goes down, your problem shouldn't be in R-L lines, connections, or cylinders. It's the pump-filter-helm-return circuit and related parts that should be looked at. With the cylinders hooked up and just turning back and forth the return back to the reservoir should be fairly consistent (slight volume need differences due to steering cylinder geometry) and if it did change, it should return to normal when you stop turning the wheel. From what you said, I assume it won't return to normal until the engine is stopped for awhile and restarted?

I wouldn't worry too much about some air in the cylinders until you diagnose the problem. If you have a considerable amount of air in them, you can check an earlier post that I had about filling the lines and cylinders without starting the engine.

As far as just getting a "tractor" helm, good luck finding the right one. See the page that Paradigm Shift referred to. There are many types and sizes. IMCO would know exactly the one to use (a Char-lynn/Eaton 4 or 5 series, no feedback, open center, 120cc or 7cu.in. per rev).

bglz42

Thanks for all your help guys!! I think I found the problem. I bought a new PS pump and swapped the check valve into mine. Steering feels very consistent now. It's still a little stiff, but maybe when I get the air out it'll get better.

Falcon, yes there is a filter. I've replaced the element, but for troubleshooting my last problem I removed the element altogether.
Thanks again for all your help!

bglz42

Ron at IMCO gave me the ag part number. My tractor supplier should be able to hook me up.

But, I think I may have it licked. I want to run the boat for a while and see if the steering effort gets easier. I did notice it got a little easer with RPM now. Before it didn't matter. Thanks!!

Mr Gadgets

Glad to hear your getting closer..

Dick

Falcon

Good to hear it's working ok. Rpm's help because of the increased flow, the increased effort is when you turn the wheel at a rate that there isn't enough output from the pump to keep up with the output to the cylinders. The "manual steering check valve" will then operate to still allow steering at a higher effort, like a sea-star type helm. Good luck!